The present invention relates to the use of halogenated 4'-methoxyacetophenones, such as 2,3'-dihalo-4'-methoxyacetophenones and 2,2,3'-trihalo-4'-methoxyacetophenones, as microbicides and preservatives.
A large number of commercial, industrial, agricultural and wood products are subject to microbiological attack which reduces or destroys their economic value. These products often contain relatively large amounts of water. Examples of materials that are subject to degradation are surface coatings, wood, agricultural seed, leather, fabrics and plastics (including flexible plastics). Examples of products sold as aqueous systems which are subject to attack are latexes, surfactants, dispersants, stabilizers, thickeners, adhesives, starches, waxes, proteins, emulsifying agents, detergents, cellulose products, and resins. These aqueous-based products generally contain organic material and are formulated in aqueous solutions, emulsions or suspensions. Specific aqueous-based products are water-based paints and metalworking fluids.
The temperature at which these products are stored and their intrinsic characteristics make them susceptible to the growth of microorganisms. These microorganisms can be introduced during the manufacturing of a product by exposure to air, tanks, pipes, equipment, and humans; and/or during the use of a product from multiple openings and reclosures of packaged products; or by the introduction of contaminated objects to stir or remove material.
Microbiological degradation of aqueous systems containing organic materials may manifest itself in a variety of problems, such as loss of viscosity, gas formation, objectionable odors, decreased pH, emulsion breaking, color change, and gelling. This degradation often renders the system ineffective for its desired use.
Another objectionable phenomenon occurring in industrial process systems involving water is slime formation. Slime consists of matted deposits of microorganisms, fibers and debris. It may be stringy, pasty, rubbery, tapioca-like, or hard; and may have a characteristic odor that is different from that of the liquid suspensions in which it is formed. Primarily, the microorganisms involved in slime formation are different species of spore-forming and nonspore-forming bacteria, particularly capsulated forms of bacteria which secrete gelatinous substances that envelop or encase the cells. Slime microorganisms also include filamentous bacteria, filamentous fungi of the mold type, yeasts, and yeast-like organisms. Slime reduces yields in industrial processes, such as paper production, and causes plugging and other problems in water systems.
Compounds containing brominated acetophenones are known in the literature as microbicides. For example, U.S. Pat. No. 3,354,033 describes the use of 2-bromoacetophenones as slime controlling agents. East German Patent DD 209,716 describes some of the 2,2-dihaloacetophenones as fungicides. However, the microbicidal properties of acetophenone derivatives having a methoxy group in the 4'-ring position, a halogen at another ring position and a halogenated acetyl group in the 1-position have not been described in the literature.